Background: Many sex workers suffer from mental health problems, but do not seek help.Aim: To examine stigma-related and non stigma-related barriers to care and perceived need for treatment among female sex workers in Switzerland.Methods: Mental health service use, barriers to care, perceived need and presence of illness, symptoms, and psychiatric diagnoses were assessed among 60 female sex workers in Zürich, Switzerland.Outcomes: Mental health service use was defined as use of psychiatric medication, psychotherapy, or substance use services for at least 1 month during the past 6 months.Results: Adjusting for symptom levels, mental health service use was predicted by lower stigma-related, not by structural, barriers as well as by more perceived need for treatment and higher age.Clinical Implications: Sex workers with mental health problems would benefit from non-stigmatizing mental health care as well as from interventions to reduce public and self-stigma associated with mental illness and sex work.Strengths and Limitations: Limitations are the cross-sectional data, limited sample size, and recruitment from an information center for sex workers.Conclusion: Interventions that aim to increase mental health service use among sex workers should take stigma variables into account.